SPEEDING was identified as a possible cause of what is believed to be one of the worlds most expensive ever road accidents when up to 2.6 million-worth of supercars ended up in a crumpled heap on a motorway in Japan. Eight Ferraris and a Lamborghini plus a Toyota Prius were among the vehicles involved in the crash, which witnesses said happened when a speeding car slid across a wet road surface. Television footage showed mangled Ferraris many of them racing red and debris spread over some 400 metres of the eastbound side of the Chugoku Expressway, the main trunk road in southern Honshu. A pack of about 20 supercars was travelling in convoy on Sunday morning on a stretch of wet highway when the leading Ferrari slid into a guardrail, police said. Those behind slammed on their brakes, but for many of them it was apparently too late. Ive never seen such a thing, highway patrol lieutenant Eiichiro Kamitani told AFP by telephone. Ferraris rarely travel in such large numbers. Kamitani said 10 people five men and five women sustained slight injuries, in the accident. It is highly possible that they were driving in couples. Many of them were probably on their way to Hiroshima, some 130 kilometres (80 miles) to the east, for a gathering of supercars there, said Kamitani. Speeding was possible but we have yet to determine the exact cause, he added. Telegraph